The impact of body mass index on metatarsalgia surgical outcomes

Several studies have suggested that an increased body mass index (BMI) is a negative factor for forefoot plantar pain but its influence in the surgical correction of metatarsalgia is unknown. The purpose of the present study is to evaluate the influence of the BMI on the surgical outcomes of metatarsalgia. It has been hypothesized that the higher the BMI, the worse the functional outcomes after metatarsalgia surgical treatment at one year follow-up.

A prospective cohort study that included all patients operated on for third rocker metatarsalgia was conducted. Weil's osteotomy was performed on all the patients operated on. The patients' pre-operative height, weight, and BMI were recorded. The patients were subsequently divided into three groups based on their BMI. There was group 1 or the normal group (18.5 > BMI ≤ 25 kg/m2), group 2 or the overweight group (25 > BMI ≤ 30 kg/m2), and group 3 or the obese group (BMI > 30 kg/m2). Pre-operative, post-operative, and differential AOFAS were used to evaluate and compare the groups. The post-operative VAS was also measured to assess pain. The correlation between the BMI and those variables was also analyzed.

After the exclusion criteria were applied, 107 patients were finally assessed. There were 22 patients (20.6%) in group 1, 52 patients (48.6%) in group 2, and 33 patients (30.8%) in group 3. No correlation was observed between the BMI and AOFAS (p > 0.05). Neither were any differences found when the three groups were compared (p > 0.05). Moreover, no correlation between the BMI and the VAS score was observed (p = 0.690).

Obesity does not negatively influence functional outcomes after surgery for metatarsalgia in short to medium term. Regardless of their BMI, patients with propulsive metatarsalgia improve in functionality after surgical treatment.